Studies on the Synthesis and Physico-Chemical Properties of Porous LiFe_0.9M_0.1P₂O₇ (M = Fe, Co, Mn, Ni) Nanoparticles

The nano-porous LiFe_0.9M_0.1P₂O₇ (M=Fe, Co, Mn, Ni) particles were successfully prepared by simple microwave assisted combustion method and studied its detailed physico-chemical properties. The phase purity, crystallinity, functional group identification was revealed through X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis. The presence of nanoporous was identified through transmission electron microscopic (TEM) images. The electrical conductivity results illustrated that LiFe_0.9Ni_0.1P₂O₇ has higher conductivity (2.85×10⁻⁷ S cm⁻¹) among the studied systems owing to their negligible grain boundary effect. The normal dielectric behaviour was observed for all the LiFe_0.9M_0.1P₂O₇ (M = Fe, Co, Mn, Ni) materials. The paramagnetic behaviour and the Fe³⁺ state of LiFe_0.9M_0.1P₂O₇ were obtained from VSM and Mössbauer spectral analysis respectively. The cyclic voltammogram suggested that the good electrochemical lithium intercalation/de-intercalation behaviour of LiFe_0.9M_0.1P₂O₇ (M=Fe, Co, Mn, Ni) electrodes in aqueous electrolytes. The obtained diffusion coefficient value is comparable with carbon based materials.